An anatomy and detailed scan for anomalies is ideally conducted at 20 weeks. If you have a high risk of an abnormality it can be performed earlier to exclude some abnormalities.
we have been for 2 scans this year and how pleased I am with the service we received. The sonographer is so nice, you never feel rushed and makes you feel very reassured, both times she took the time to explain everything and even when the baby was in an awkward position nothing was to much trouble.